<a href=http://onlineslangdictionary.com/meaning-definition-of/ragtop>ragtop</a> To link to this term in a wiki such as Wikipedia, insert the following. [http://onlineslangdictionary.com/meaning-definition-of/ragtop ragtop] Some wikis use a different format for links, so be sure to check the documentation.
Talc (1), the softest mineral on the Mohs scale has a hardness greater than gypsum (2) in the direction that is perpendicular to the cleavage. Diamonds (10) also show a variation in hardness (the octahedral faces are harder than the cube faces).
A mineralâs hardness is related to the strength of its weakest bond, and minerals may have different hardnesses in different directions. For example, kyanite has a hardness of 5.5 if scratched lengthwise, but a hardness of 6.5 if scratched crosswise (numbers in Mohs scale). Since covalent bonds are stronger than ionic bonds, minerals in which covalent bonds dominate will be harder than those in which ionic bonds are prevalent.